Glaucoma is a disease that needs to be caught early and treated quickly. Could your pet be susceptible?
Pet glaucoma comes in two forms:
- Primary glaucoma (which is inherited and breed-related)
- Secondary glaucoma (caused by some other condition affecting the eyes)
The two glaucomas affect dogs at a rate of 1.7%. A study of 27 breeds showed that on average primary (breed-related) glaucoma affected 0.71% of dogs. However, in some breeds, it was much higher:
- American Cocker Spaniel (5.52%)
- Basset Hound (5.44%)
- Chow Chow (4.70%)
- Shar-Pei (4.40%)
- Boston Terrier (2.88%)
Females were more often affected in certain breeds. The disease generally appears between ages 4 and 10, at an average age of 6.
Primary glaucoma is rare in cats but shows a slight prevalence in Burmese and Siamese breeds. Most feline glaucoma is secondary and is typically linked to chronic inflammation of the eye, or uveitis. Less than 0.3% of the cat population is affected by the two glaucomas. However, the clinical signs in cats are very subtle, so the disease tends to be caught later, resulting in a poor prognosis for saving your pet’s eyesight.
Insurance Coverage and Costs of Glaucoma Treatment?
Primary glaucoma treatment is usually covered by pet insurance policies that include hereditary conditions. Examples are ASPCA’s Compete Coverage, Healthy Paws and Embrace, as long as no symptoms were present upon enrollment or during the waiting period. Nationwide does not. Secondary glaucoma (triggered by another condition) would be covered as an illness under most standard policies, again if not deemed to be pre-existing.
If you think your pet has a predisposition to glaucoma, question any future insurance provider carefully to be sure treatment will be covered if glaucoma occurs.
What are the Costs Related to Glaucoma Treatment?
Beyond initial consultations, medications are the least-cost solution, but will likely not prevent eventual blindness without surgery. Eye Specialists for Animals lists diode laser treatment performed under general anesthesia at $1,300. Chemical oblation under light sedation costs $900 (one eye) to $1,300 (both eyes). Eye removal (enucleation) runs $1,900-$2,100.
What Is Glaucoma?
Glaucoma is a disease where pressure builds inside your pet’s eye because the fluid (aqueous humor) produced inside the eye does not drain properly. Aqueous humor provides nutrients to eye tissues and helps shape the eye. Untreated, it will cause the eye to enlarge, lose its shape, and eventually lead to total blindness.
The eye pressure (or intraocular pressure, IOP) reaches higher levels in pets than what humans experience and likely causes migraine-like headaches. However, our pets mask pain very well, so you must look for subtle signs: rubbing or pawing at the face, squinting, unwillingness to play, loss of appetite, a single dilated pupil or a bulging eye.
Catching glaucoma early is critical since some forms can escalate very quickly, sometimes within hours. With dogs, 40% of diagnosed cases lead to blindness within a year, and in 50% it will spread to the second eye if not treated.
How is Glaucoma Diagnosed and Treated?
If your pet’s glaucoma is secondary, the cause (inflammation, infection, etc.) will first have to be identified and treated. Then any damage can be assessed and corrected, if possible.
With primary glaucoma, the vet will measure the eye pressure. An x-ray or ultrasound can rule out an eye abscess, injury, or tumor. Then a test called gonioscopy can measure the chances of losing the second eye.
Treatment depends on the cause and severity. Medications (topical drops or ointments) are the first approach. Then comes surgery, if called for: laser (for dogs only) or chemical ablation to stop fluid production, or implants of a small tube to assist drainage. The last resort is the complete removal of the eyeball, which pets handle surprisingly well.
Additional Offline Sources:
Essentials of Veterinary Ophthalmology, edited by Kirk N. Gelatt, John Wiley * Sons, Apr 2, 2013.
Feline Glaucoma, by Gillian J. McLellan, Ph.D., and Leandro B.C. Teixeira, DVM, Elsevier, Veterinary Clinics of North America: Small Animal Practice, Vol 45, Issue 6, November 2015.